Clips have been used to retain and support tubular lines such as hydraulic brake lines or fuel lines which run along the undercarriage of a vehicle. Metal brackets have been used to individually or in bundles secure each line to the vehicle undercarriage. Unfortunately such brackets are susceptible to corrosion and fatigue which can cause bracket failure leaving a tube previously retained by the bracket unsupported. Over time, unsupported tubes can rupture possibly causing brake failure or dangerously leaking fuel. Metal clips are also disadvantageous because their rigid mounting to the undercarriage makes any servicing of the tubes carried by the brackets very difficult without destroying the bracket requiring replacement.
More recently, plastic clips have been used to retain and support brake and fuel lines. These clips have been utilized because of their non-corrosive and light-weight characteristics and economical manufacture. A first type of clip commonly used has a body with one or more recesses for receiving a tube therein. To retain the tube when received within a recess, one finger on each side of the recess forms a generally V-shaped entry channel to the recess allowing a tube to be snapped into the recess with the bottom portion of each finger generally abutting against the outer peripheral surface of the tube to prevent removal of the tube from the recess. The second type of clip has a two piece body connected together by a living hinge and a latch. There are recesses in each piece which generally axially align to form cylindrical tube retaining channels when one piece is placed in overlapping fashion over the opposite piece. In use, tubes are placed in one set of recesses and the two hinged pieces are pivotally moved and latched together with the latch.
When retained by a clip, tubes under load can transmit a considerable amount of force to the clip along a line generally perpendicular to the axis of each tube. In this dynamic state each tube can transmit a force in a different direction thereby possibly increasing the amount of force transmitted to the clip latching mechanism and creating a moment along an axis where the clip generally engages each tube. Since the latching mechanism engages the clip body or directly retains each tube along a direction generally parallel to the axis of each tube, a sufficient amount of force or a moment transmitted to the clip generally perpendicular to the latch mechanism can cause the latch to disengage and free one or more tubes.
Typically, these clips are constructed of nylon which may become brittle with age. As a clip of nylon ages, less force may be required to disengage a latch which has degraded or become brittle. A living hinge in this state can also fail releasing the tubes from the clip. Furthermore, servicing of a tube, such as replacing a brake or a fuel line, requires the disassembly of the clip to remove the tube possibly weakening an embrittled latch mechanism or the living hinge. Later when reassembled in such a weakened state the clip is more susceptible to failure.
The problems commonly encountered with these clip designs such as corrosion, fatigue, or embrittlement can cause the clip to fail releasing the tubes retained by it. As a result of the locking mechanisms of the plastic clips securing the tube to the clip body along a direction generally parallel to the axis of each tube, dynamic loading such as during vehicle operation can cause the latching mechanism to disengage releasing the tubes retained by the clip.